The concept of "patient enablement" involves patients' perceptions of ability to understand and cope with illness. Improving enablement is an important goal of medical consultations for patients with chronic illness. To measure "enablement," a post-medical-consultation patient-reported questionnaire was developed and named "Patient Enablement Instrument (PEI)" in the United Kingdom. Unfortunately, there has been no tool to evaluate patient enablement in Japan. Therefore, this study aimed to develop PEI Japanese version, to examine its validity and reliability, and to clarify the constitution of concept about patient enablement among Japanese patients. The translation process included forward translation, expert panel back-translation, following the standard WHO process. Participants were 256 individuals (157 men and 99 women; mean age 62.9 ± 11.8 years) receiving a regular outpatient treatment due to chronic illness at the Department of Cardiology, Respiratory, or Endocrinology and Metabolism in a regional hospital. To assess validity, we compared PEI with Medical Interview Satisfaction Scale (MISS) by correlation coefficient, which was 0.55 (P < 0.01). Furthermore, factor analysis indicated that PEI had two principal factors labeled "coping with illness and health maintenance" and "confidence in oneself and independence". For an evaluation of reliability, internal consistency was calculated (Cronbach's alpha = 0.875). In conclusion, two principal factors comprise patient enablement measured by PEI with satisfactory validity and reliability. PEI Japanese version will be a useful tool to evaluate and improve medical consultations in Japan.